 # Quick Answer: How Do You Find Sin 75?

## What is the formula for 2 cos a sin B?

2 cosA sinB = sin(A + B) − sin(A − B) 2 cosA cosB = cos(A + B) + cos(A − B) 2 sinA sinB = cos(A − B) − cos(A + B).

## What is the value of cosine?

The function f(x) = cosx has all real numbers in its domain, but its range is −1 ≤ cosx ≤ 1. The values of the cosine function are different, depending on whether the angle is in degrees or radians. The function is periodic with periodicity 360 degrees or 2π radians.

## What is the exact value of sin degrees?

Sine 30 Degrees Value The exact value of sin 30 degrees is ½. To define the sine function of an angle, start with a right-angled triangle ABC with the angle of interest and the sides of a triangle.

## What is the formula for calculating sine?

In any right angled triangle, for any angle:The sine of the angle = the length of the opposite side. the length of the hypotenuse.The cosine of the angle = the length of the adjacent side. the length of the hypotenuse.The tangent of the angle = the length of the opposite side. the length of the adjacent side.

## What is sin 2a?

⇒ sin 2A = 2 sin A cos A. Note: In the above formula we should note that the angle on the R.H.S. is half of the angle on L.H.S. Therefore, sin 60° = 2 sin 30° cos 30°. The above formula is also known as double angle formulae for sin 2A.

## How do you solve sin 50 without a calculator?

Here’s how you you can find it without calculator. Draw a right angeled triangle with one angle equal to 50 degree and side of any measurment. Now ,measure the perpendicular and hypotenous and calculate their ratio. Thats all.

## How do you calculate sin by hand?

Simply to use a special form of the sum of angles formula, called the double-angle (or half-angle) formula: sin(2x) = sin(x+x) = 2*sin(x)*cos(x) cos(2x) = 2*cos(x)^2 – 1 If you solve for sin(x) and cos(x): sin(x) = sqrt( (1-cos(2x))/2) cos(x) = sqrt((1+cos(2x))/2) So, say we have cos(15); then I can get sine and cosine …

## How do you find the value of sin 75?

Sin(A+B) = Sin A Cos B + Cos A Sin B. Sin 75 = Sin ( 45 + 30) = Sin 45 Cos 30 + Cos 45 Sin 30. Sin 75 = (1 / √2) ( √3 / 2) + (1 / √2) ( 1 / 2) = [ √3 + 1] / 2√2.

## What is an exact value?

Definition. Exact value is where you cannot estimate the value you must be precise, eg; you can’t estimate something as being around about 5 centimetres; no you need an exact value such as 5.62. Exact value. Return to Mathematics Home.

## What is the formula of Cos 2a?

Both sin (2A) and cos (2A) are derived from the double angle formula for the cosine: cos (2A) = cos2(A) − sin2(A) = cos2(A) − (1 − cos2A) = 2cos2(A) − 1.

## How do you find cosine of an angle?

Cosine (cos) function – Trigonometry. In a right triangle, the cosine of an angle is the length of the adjacent side (A) divided by the length of the hypotenuse (H). Try this Drag any vertex of the triangle and see how the cosine of A and C are calculated.

## How do you find the value of tan15?

Value of Tan 15Tan (15°) can be found if we know the value of sin 15 degrees and cos 15 degrees. … From the above table, we have the values of tan, sin and cos ratios for 0°, 30°, 45°, 60° and 90°. … tan (15°) = √3 – 1/ √3 + 1.Hence, the value of tan (15°) is √3 – 1/√3 + 1.∴ Tan (15°) = (1.732 – 1)/(1.732 + 1) = 0.2679.More items…

## What is cos 2x identity?

cos(2x) = cos^2(x) – sin^2(x) = 2 cos^2(x) – 1 = 1 – 2 sin^2(x) tan(2x) = 2 tan(x) / (1 – tan^2(x))

## Is the value of tan 30?

The exact value of tan 30° is 0.57735. The value of tangent of angle 30 degrees can also be evaluated using the values of sin 30 degrees and cos 30 degrees.

## What is an exact answer?

It means that you leave your answer in the form of a fraction or radicals (square root symbol) — instead of a decimal answer.